Research on the hysteretic performance of flower-gusset composite joints for single-layer aluminium alloy lattice shell structures

Joints are the most critical component of reticulated shell structures, and their hysteretic performance is crucial to the mechanical properties of the whole reticulated shell structure under seismic action. Therefore, the hysteretic behaviour of aluminium alloy flower-gusset composite joint for an out-of-plane bending moment was studied by experiments and numerical analysis. The results show that the hysteretic curves of flower-gusset composite joints and gusset joints contain four stages: an elastic stage, a bolt slip stage, a hole wall pressure-stiffness degradation stage and a failure stage. The hysteretic performance of the new flower-gusset composite joint is obviously better than that of the traditional plate joint. With the increase in the thickness of the cover plate, the bending stiffness of the flower-gusset composite joint increases significantly, while the rotational deformation decreases. Then, a restoring force model of the flower-gusset composite joint is proposed through theoretical analysis based on experiments and numerical analysis.